03 Navigator. What would be some of the root causes of sudden acceleration? I know the RPM's should fluctuate slightly when the compressor kicks in and out as well as and other engine functions. But something is causing a random spike in RPM's.
For example: at a red light if you aren't holding the brake tightly, it will try to lunge forward; and at curb idle (transmission in park) the RPM's will rev up like it does when you start the engine for the first time on a cold day.